In today's highly sophisticated, complex and intelligent automation systems, industrial controllers have powerful tools and features that could be simplified through the use of RFID (radio frequency identification). When implementing an RFID solution in a distribution center or a factory, it is customary to utilize three distinct platforms: an RFID reader/antenna, RFID “middleware” running on a standard PC (personal computer), and a PLC (programmable logic controller). Each platform requires its own configuration and management resulting in higher costs in implementation and support (e.g., by wiring and labor for three platforms, different environments, and operator training). Moreover, the reader and PC may not be ruggedized for an industrial environment.
The traditional approach is to have an RFID reader connection to the PLC via a network using, for example, RS-232 serial communications, Ethernet, or any of the field buses such as DeviceNet, ControlNet, etc. Using such technologies typically involves the use of interface cards and/or logic that requires software control, power needs, and additional hardware maintenance. Moreover, in that there are other communications links involved, it is possible to have missed packets, in addition to the implementation of slower communications speeds due to these links or network dependencies. The interface between an RFID reader and a PLC must be both fast and reliable. The speed determines the rate at which RFID tags can be read and the reliability of this interface determines the usability of the RFID information. By using shorter communications pathways and such pathways that can be dedicated, it is possible to achieve higher bandwidth communications. Accordingly, there is an unmet need in the art for an improved RFID system in the automation regime.